Chemistry Commons^™

Rebecca Roesner And Advancing Diversity In The Chemical Sciences, Ryan Denham

Interviews for WGLT

Rebecca Roesner, chair and professor of chemistry at Illinois Wesleyan University, has earned the Stanley C. Israel Regional Award for Advancing Diversity in the Chemical Sciences for her work furthering diversity and inclusivity. Professor Roesner spoke about the award, and her part in helping to promote diversity in the sciences with Ryan Denham from WGLT Radio.

Understanding How Map Kinases Influence Endothelial Nitric-Oxide Synthase Activity, Xzaviar Solone

Master of Science in Integrative Biology Theses

Mitogen activated protein kinases (MAPK) p38 and ERK have both been reported to bind endothelial nitric oxide synthase (eNOS) with submicromolar affinity via proposed interactions with a pentabasic non-canonical MAPK binding sequence in the autoinhibitory insertion of eNOS. The neuronal isoform, which lacks the pentabasic motif, did not bind either MAPK significantly. In the present study, the pentabasic motif was validated using predictive modeling programming, and eNOS phosphorylation by MAPKs (P38, ERK and JNK) was examined using in vitro kinase assays and immunoblotting. JNK phosphorylation at Ser¹¹⁴ contrasts with ERK, which phosphorylated Ser⁶⁰⁰, and p38, which phosphorylated …

Peppytides, Dave Zwicky

2019 Symposium on Electronic Theses and Dissertations

Lightning talk for Symposium on Electronic Theses and Dissertations (ETD) at Purdue University on May 23, 2019.

Effects Of Polyamine Binding On The Stability Of Dna I-Motif Structures, Michael M. Molnar, Shelby C. Liddell, Randy M. Wadkins

Faculty and Student Publications

B-form DNA can adopt alternative structures under conditions such as superhelical duress. Alternative DNA structures are favored when there is asymmetric distribution of guanosine and cytosine on complimentary DNA strands. A guanosine-rich strand can form a four-stranded structure known as a quadruplex (G4). The complimentary cytosine-rich strand can utilize intercalating cytosine−cytosine base pairing to form a four-stranded structure known as the i-motif (iM). Both secondary structures are energetically uphill from double-strand DNA (dsDNA), meaning that additional factors are needed for their formation. Most iMs require slightly acidic conditions for structure stabilization. However, crowding agents such as polyethylene glycols and dextrans …

A New Magnetic Topological Quantum Material Candidate By Design, Weiwei Xie, Xin Gui

Faculty Publications

Magnetism, when combined with an unconventional electronic band structure, can give rise to forefront electronic properties such as the quantum anomalous Hall effect, axion electrodynamics, and Majorana fermions. Here we report the characterization of high-quality crystals of EuSn2P2, a new quantum material specifically designed to engender unconventional electronic states plus magnetism. EuSn2P2 has a layered, Bi2Te3-type structure. Ferromagnetic interactions dominate the Curie-Weiss susceptibility, but a transition to antiferromagnetic ordering occurs near 30 K. Neutron diffraction reveals that this is due to two-dimensional ferromagnetic spin alignment within individual Eu layers and antiferromagnetic alignment between layers-this magnetic state surrounds the Sn-P layers …

The Development Of Silica Hydride Stationary Phases For High-Performance Liquid Chromatography From Conception To Commercialization, Maria Matyska-Pesek, Joseph Pesek

Faculty Publications, Chemistry

The development of a stationary phase material for high-performance liquid chromatography based on a surface of silica hydride as opposed to silanols on ordinary silica is discussed including synthetic approaches, characterization, and applications. There are several synthetic approaches available to create a silica hydride surface. Modification of the Si–H moiety on the silica surface can be accomplished through the use of a hydrosilation reaction. Both the intermediate silica hydride and the material modified with an organic moiety can be characterized by a number of spectroscopic as well as a variety of other methods. Further insights into the retention mechanism are …

Elemental And Oxidized Mercury In Ambient Air At Rocky Flats, Colorado, Seth Lyman, Lynne Gratz

Browse all Datasets

This is a dataset of elemental and oxidized mercury in the ambient atmosphere at latitude 39.912799 and longitude -105.188587. This is the locations of the Rocky Flats North air quality monitoring station, operated by the Colorado Department of Public Health and Environment. We collected these measurements using a dual-channel atmospheric mercury speciation instrument.

Mechanism Of Electrospray Supercharging For Unfolded Proteins: Solvent-Mediated Stabilization Of Protonated Sites During Chain Ejection., Insa Peters, Haidy Metwally, Lars Konermann

Chemistry Publications

Proteins that are unfolded in solution produce higher charge states during electrospray ionization (ESI) than their natively folded counterparts. Protein charge states can be further increased by the addition of supercharging agents (SCAs) such as sulfolane. The mechanism whereby these supercharged [M + zH] ^z+ ions are formed under unfolded conditions remains unclear. Here we employed a combination of mass spectrometry (MS), ion mobility spectrometry (IMS), and molecular dynamics (MD) simulations for probing the ESI mechanism under denatured supercharging conditions. ESI of acid-unfolded apo-myoglobin (aMb) in the presence of sulfolane produced charge states around 27+, all the way to fully …

Triperyleno[3,3,3]Propellane Triimides: Achieving A New Generation Of Quasi-D3h Symmetric Nanostructures In Organic Electronics, Lingling Lv, Josiah Roberts, Chengyi Xiao, Zhenmei Jia, Wei Jiang, Chad Risko, Lei Zhang

Chemistry Faculty Publications

Rigid three-dimensional (3D) polycyclic aromatic hydrocarbons (PAHs), in particular 3D nanographenes, have garnered interest due to their potential use in semiconductor applications and as models to study through-bond and through-space electronic interactions. Herein we report the development of a novel 3D-symmetric rylene imide building block, triperyleno[3,3,3]propellane triimides (6), that possesses three perylene monoimide subunits fused on a propellane. This building block shows several promising characteristics, including high solubility, large π-surfaces, electron-accepting capabilities, and a variety of reactive sites. Further, the building block is compatible with different reactions to readily yield quasi-D_3h symmetric nanostructures (9, …

Growth Factors In The Human Body: A Conceptual Update, Estefania Alexandre, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Growth factors are found in most of the organisms including insects, humans, plants, etc. The name ‘growth factors’ became known when the substances were active in stimulating the growth of cells and tissues. Growth factors are regulatory species (signaling molecules mainly proteins) that are generated by the body which function in binding to receptors on the cell surface and are required to stimulate the growth in living responsive cells by triggering cellular proliferation and/or cellular differentiation pathways, as well as by regulating gene transcription in the nucleus. They are quite versatile by promoting cell growth and act in a paracrine, …

Expanding The Toolbox With Site-Specific Methods Of Bioconjugation, Tiauna S. Howard

Seton Hall University Dissertations and Theses (ETDs)

Bioconjugation is an important tool for studying complex biological systems, with site-specificity being the major challenge. Reactions based on amino acid derived organocatalysts have been widely used in organic synthesis, particularly for the asymmetric synthesis of small molecules but this concept has not been vastly explored on biomolecules. To combat these limitations, two chemical strategies are developed to effectively attach synthetic molecules site specifically to proteins. First, a protein modification technique based on conjugation at a non-native functional handle, an aldehyde or ketone, is developed. This functional handle is chemically introduced onto the biomolecules before undergoing the organocatalyzed aldol reaction, …

Determination Of Anxiolytic And Antidepressant Medicines In New York City Wastewater Samples, Jasmine J. Gayle

Student Theses

Wastewater-based epidemiology (WBE) provides information about a population’s exposure to certain chemical agents, such as drugs of abuse and medicines, by the analysis of human biomarkers, also known as excretion products, in wastewater samples. Although this is a growing field worldwide, mainly in Europe, Oceania, and Asia, limited data from the US are currently available. We developed and validated an analytical method to quantitatively and qualitatively determine the presence of commonly prescribed drugs to treat anxiety (alprazolam, buspirone, clonazepam, lorazepam, and propranolol) and depression (bupropion, citalopram, clomipramine, duloxetine, fluoxetine, imipramine, paroxetine, sertraline, and venlafaxine) in wastewater using liquid chromatography tandem …

Electrophilic Oligodeoxynucleotide Synthesis Using Dm-Dmoc For Amino Protection, Shahien Shahsavari, Dhananjani N. A. M. Eriyagama, Bhaskar Halami, Vagarshak Begoyan, Marina Tanasova, Jinsen Chen, Shiyue Fang

Department of Chemistry Publications

Solid-phase synthesis of electrophilic oligodeoxynucleotides (ODNs) was achieved using dimethyl-Dmoc (dM-Dmoc) as amino protecting group. Due to the high steric hindrance of the 2-(propan-2-ylidene)-1,3-dithiane side product from deprotection, the use of excess nucleophilic scavengers such as aniline to prevent Michael addition of the side product to the deprotected ODN during ODN cleavage and deprotection was no longer needed. The improved technology was demonstrated by the synthesis and characterization of five ODNs including three modified ones. The modified ODNs contained the electrophilic groups ethyl ester, α-chloroamide, and thioester. Using the technology, the sensitive groups can be installed at any location within …

Hypervalent Iodine(Iii) Compounds With (Pseudo)Halide And Tetrazole Ligands In The Synthesis Of Functional Polymers, Rajesh Kumar

Chemistry Theses and Dissertations

The organic compounds of iodine(III) with the general formula ArIL₂ (Ar = aryl, L = (pseudo) halides) degrade homolytically upon irradiation or heating to the corresponding monovalent iodine compound (ArI) and the radicals L^• . If the latter contains a functional group, they can be used to initiate the polymerization of vinyl monomers to afford chain end-functionalized linear polymers. When "conventional" monovinyl monomers are copolymerized with di- or multivinyl monomers (crosslinkers) in the presence of relatively high concentrations of rapidly decomposing ArIL₂ compounds, highly branched polymers are formed that contain multiple chain-end functionalities derived from the radicals …

Fluorescence Of Naphthol As-Mx Is Readily Detectable In Dioxane Mixtures, Evan D. Kindl, Kevin E. Koschnitzke, James A. Blauwkamp, Sean M. Mccann, Veronica R. Moorman

Chemistry & Biochemistry Publications

Numerous enzymes have been demonstrated to be active in non-aqueous solutions, yet the utility of phosphatases under such conditions has been difficult to determine. Here, we demonstrate the ability to fluorescently detect naphthol AS‑MX in high percentages 1,4-dioxane with a fluorescence differential compared with naphthol AS‑MX phosphate. While intensities and maximum fluorescence wavelengths changed depending on solvent conditions, these results demonstrate this system’s potential for testing phosphatase activity in high amounts of dioxane.

Ni-Catalyzed Cross-Electrophile Coupling For The Synthesis Of Skipped Polyenes, Catherine P. Mcgeough, Alexandra E. Strom, Timothy F. Jamison

Chemistry: Faculty Publications

Skipped polyenes featuring high (E)-selectivity and varying methyl substitution patterns are synthesized using a nickel-catalyzed cross-coupling reaction between allyl trifluoroacetates and vinyl bromides. The utility of this cross-electrophile coupling is showcased in part by the synthesis of the RST fragment of the marine ladder polyether, maitotoxin. Construction of this fragment is particularly challenging due to the alternating methyl substitution pattern.

Phantoms In Science: Nietzsche's Nonobjectivity On Planck's Quanta, Donald Richard Dickerson Iii

Undergraduate Theses

What does Maxwell Planck's concept of phantomness suggest about the epistemological basis of science and how might a Nietzschean critique reveal solution to the weaknesses revealed? With his solution to Kirchoff's equation, Maxwell Planck launched the paradigm of quantum physics. This same solution undermined much of current understandings of science versus pseudoscience. Using Nietzsche's perspectivism and other philosophical critiques, Planck's answer to blackbody radiation is used to highlight the troubles with phantom problems in science and how to try to direct science towards a more holistic and complete scientific approach.

Synthesis, Stabilization, And Modification Of Zinc Oxide Nanoparticles For Biological Applications, Allison Kimberly Freese

Graduate Theses/Dissertations

Nanoparticles have become very useful as delivery systems in biomedicine. The nanoparticles can be layered with different compounds to produce a vessel for transport of biological materials. Specifically, gold nanoparticles layered with a reducing agent, lysozyme, and polyelectrolytes can be synthesized to transport lysozyme into a cell. However, zinc oxide nanoparticles are cheaper, biocompatible nanoparticles that can be used for the same process. Here in, zinc oxide nanoparticle conjugates were synthesized, modified, and analyzed to be used as a biological material delivery system. The zinc oxide nanoparticles were synthesized using zinc chloride and sodium hydroxide. The particles were then layered …

Melt Electrospinning Designs For Nanofiber Fabrication For Different Applications, Yasseen S. Ibrahim, Essraa A. Hussein, Moustafa M. Zagho, Ghada G. Abdo, Ahmed A. Elzatahry

Faculty Publications

Nanofibers have been attracting growing attention owing to their outstanding physicochemical and structural properties as well as diverse and intriguing applications. Electrospinning has been known as a simple, flexible, and multipurpose technique for the fabrication of submicro scale fibers. Throughout the last two decades, numerous investigations have focused on the employment of electrospinning techniques to improve the characteristics of fabricated fibers. This review highlights the state of the art of melt electrospinning and clarifies the major categories based on multitemperature control, gas assist, laser melt, coaxial, and needleless designs. In addition, we represent the effect of melt electrospinning process parameters …

An In-Situ Study Of The Aqueous Speciation Of Uranium (Vi) Under Hydrothermal Conditions, Diwash Dhakal

Graduate Theses/Dissertations

Rigorous study of the speciation distribution of uranyl-chloride bearing solutions under hydrothermal conditions is important to understand the transport mechanism of uranium underground, which is of uttermost interest to parties studying the geological uranium deposits and those studying the possibilities of geological repositories for spent nuclear waste. I report an in-situ Raman spectroscopic study of the speciation distribution of aqueous uranyl-chloride complexes upto 500°C conducted using a HDAC as the high PT spectroscopic cell. The samples studied contained the species UO₂²⁺, UO₂Cl⁺, UO₂Cl₂⁰ and UO₂Cl₃^{- …}

Concentration-Dependent Magnetic Properties Of Mnxnio1-X Novel Inverted Core-Shell Nanoparticles, Md Nazmul Alam

Graduate Theses/Dissertations

The doping concentration (Mn concentration) dependent magnetic properties of NiO@NixMn1-xO novel inverted core-shell magnetic nanoparticles are of great interest of this present research. Primarily, we investigated the oxidation state of Ni from size-dependent four NiO NPs samples, and then studied the variation in the magnetic properties of Mn concentration-dependent NiO@NixMn1-xO CNPs. The NiO nanoparticles were synthesized using a thermal decomposition method. The XRD data indicates that the crystal structure (rock salt) remains fixed in all NiO samples and XPS data shows the oxidation state of size-dependent NiO nanoparticles is 2+. The hydrothermal epitaxy method was used to incorporate Mn in …

Photo-Physical Properties Of Novel Gumbos For Optoelectronic Applications, Thenahandi Prasanthi Deepthika De Silva

LSU Doctoral Dissertations

Organic Light Emitting Diodes (OLEDs) are predicted to revolutionize next generation consumer electronics by offering many advantageous device characteristics, including low power consumption, low heat dissipation, a tunable and wider color gamut, high resolution and contrast, light weight, flexibility, and semi-transparency. However, a major limiting factor for OLEDs to reach their full potential is that only a few known blue OLED emitters with substantial spectral purity and longevity are available to date. Therefore, focus of this research is on understanding and addressing limitations of OLED emitters, with an emphasis on improving the characteristics of blue emitters.

The work presented in …

Defect Chemistry And Ion Intercalation During The Growth And Solid-State Transformation Of Metal Halide Nanocrystals, Bo Yin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Abstract of the Dissertation

Defect Chemistry and Ion Intercalation During the Growth and Solid-State Transformation of Metal Halide Nanocrystals

Semiconductor metal halides as light-sensitive materials have applications in multiple areas, such as photographic film, antibacterial agents and photocatalysts. One focus of this dissertation is to achieve novel morphologies of ternary silver bromoiodide (AgBr1-xIx, 0

For the silver halide system, we demonstrate that the anion composition of AgBr1-xIx nanocrystals determines their shape through the introduction of twin defects as the nanocrystals are made more iodide-rich. AgBr1-xIx nanocrystals grow as single-phase, solid solutions with the rock salt crystal structure for anions compositions …

Siderophore Pathways And Non-Traditional Antibiotic Strategies In Multi-Drug Resistant Acinetobacter Baumannii, Tabbetha Bohac

Arts & Sciences Graduate Student Theses and Dissertations

The rise of antibiotic resistance is driving exploration of non-canonical antibiotic approaches, including neutralization of virulence factors. Multi-drug resistant (MDR) Gram-negative pathogens, including Acinetobacter baumannii, are of particular concern because of the small number of clinically useful antibiotics available for use. Here we both expand upon the existing knowledge of two of the siderophores of A. baumannii, acinetobactin and fimsbactin, and utilize this knowledge to synthesize novel compounds for the inhibition of pathogenic A. baumannii in whole cell assays.Furthering the current knowledge of the natural siderophore systems of A. baumannii, we were able to investigate the interaction of acinetobactin with …

Isotopically-Resolved Neutron Cross Sections As Probe Of The Nuclear Optical Potential, Cole Davis Pruitt

Arts & Sciences Graduate Student Theses and Dissertations

Neutron scattering experiments provide direct access to the forces experienced by nucleons in the nuclear environment. Due to the experimental difficulty of cross section measurements with neutrons, isotopically-resolved neutron scattering cross sections are sorely needed as inputs for many nuclear models. This dissertation presents the results from a campaign of isotope-specific neutron total cross section measurements on 16,18O, 58,64Ni, 112,124Sn, and 103Rh from 3-450 MeV and elastic scattering differential cross section measurements on 112,nat,124Sn at 11 and 17 MeV. Equipped with these new data and with computational improvements to the Dispersive Optical Model (DOM), we present DOM treatments of 16,18O, …

Solid-State Nmr Study On Solid Amine Sorbents, Chia-Hsin Chen

Arts & Sciences Graduate Student Theses and Dissertations

Solid-state NMR spectroscopy is a useful structural tool, with a high sensitivity to the local atomic-scale environment providing a powerful probe of structure, disorder, and dynamics of solids. In this dissertation, solid-state NMR was used to characterize chemisorbed products of solid amine sorbents exposed to CO2. Solid amine sorbents are promising candidates to capture CO2 for the purposes of mitigation of this greenhouse gas in high-concentration sources, such as flue gases emitted from power plants or industrial sites. Understanding the adsorption process of these solid materials is critical to help design better materials to have a higher CO2 uptake.A series …

Oxidative C–C And C–Heteroatom Reactivity Of High-Valent Nickel Complexes, Sofia Marie Smith

Arts & Sciences Graduate Student Theses and Dissertations

ABSTRACT OF THE DISSERTATIONOxidative C–C and C–Heteroatom Reactivity of High-Valent Nickel ComplexesbySofia M. SmithDoctor of Philosophy in ChemistryWashington University in St. Louis, 2019Professor Liviu M. Mirica, ChairProfessor Kevin D. Moeller, Co-ChairNickel catalysts are commonly used for cross-coupling reactions such as Negishi, Kumada and Suzuki couplings. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, Ni(III) and Ni(IV) species have also been recently proposed to play a role in catalysis. The formation of C–C and C–heteroatom bonds plays a fundamental role in organic transformations, and today cross-coupling reactions are one of the most powerful tools for the construction …

Synthesis Of A Protein Based Photocatalytic Hydrogen Production System, Alexander M. Brown

Honors Program Theses and Projects

Anthropogenic climate change is one of the most pressing challenges facing humans today. It is scientifically established that the production of copious amounts of greenhouse gases such as carbon dioxide (CO2) is the primarycause of global warming. Many of these greenhouse gases are produced from the combustion of carbon-based fuels and researchers are investigating promising alternative fuel sources such as hydrogen gas. Hydrogen gas is a clean burning fuel that stores a significant amount of chemical potential energy. The goal of this project was to synthesize a protein based photocatalytic hydrogen production system and to characterize the effects of modifications …

Synthesis Of Novel Reiii And Rev Metallointercalator Complexes For Use As Dna Damage Probes, Eli Schwartz

Honors Program Theses and Projects

Cancer is a disease that affects millions around the globe. Treatments such as radiation and chemotherapy are often used to treat cancerous tumors, but are not 100% effective in curing the patient. Alternatively, some research groups have proposed the use of metallointercalators, metal complexes consisting of a rhodium, ruthenium, or iridium metal center with bidentate supporting ligands such as bipyridine and phenanthroline, or tridentate ligands such as terpyridine. The complexes also contain a bidentate intercalating group such as dipyridophenazine. These complexes possess the ability to directly bind to DNA through intercalation between the stacks of DNA base pairs, giving them …

Pressure-Induced Phase Transition In 1,3,5-Triamino-2,4,6-Trinitrobenzene (Tatb), Brad A. Steele, Samantha M. Clarke, Matthew P. Kroonblawd, I-Feng W. Kuo, Philip F. Pagoria, Sergey N. Tkachev, Jesse S. Smith, Sorin Bastea, Laurence E. Fried, Joseph M. Zaug, Elissaios Stavrou, Oliver Tschauner

Geoscience Faculty Research

Determining the unreacted equation of state of 1,3, 5-triamino-2,4,6-trinitrobenzene (TATB) is challenging because it exhibits low crystal symmetry and low X-ray scattering strength. Here, we present the first high-pressure single-crystal X-ray diffraction (SXD) study of this material. Our SXD results reveal a previously unknown transition to a monoclinic phase above 4 GPa. No abrupt change of the volume occurs but the compressibility changes. Concomitant first principles evolutionary crystal structure prediction USPEX calculations confirm this transition and show that it involves a pressure-induced in-plane shift of the layers of TATB molecules with respect to the ambient-pressure phase.